With development of the communications industry, higher requirements are imposed on reliability of communications products. Communications products are generally delivered to all regions, and need to adapt to global weather and environment, which requires that communications die-casting fittings are corrosion resistant to sea water and acid rain, have good heat dissipation performance to adapt to a thermal shock change, have certain mechanical properties to satisfy wind load fatigue, and the like. In view of satisfying requirements of various comprehensive properties of the communications die-casting fittings, a die-casting base material needs to have characteristics of high heat conductivity, good corrosion resistance, and certain mechanical properties. In addition, generally, the communications die-casting fitting has a complex structure, has a large number of complex thin-wall heat sink fins, high and low bosses, and deep-cavity structures, and therefore, the die-casting base material needs to have good formability. Costs of the base material are also a factor to be considered in large-scale and global delivery. In view of the foregoing requirements, a die casting aluminum alloy is the first choice.
However, it is hard for an existing die casting aluminum alloy to have properties in various aspects, for example, aluminum alloys with three designations, namely, YL102, YL113, and YL117 in Chinese standards, have excellent formability, but poor corrosion resistance, which cannot satisfy requirements of application of the communications die-casting fitting in coastal environment, acid rain, and the like. In die casting aluminum alloys with foreign designations, for example, an European Union standard EN 43400 has poor formability; EN 44300 has excellent formability, and heat conductivity of the EN 44300 also satisfies requirements, but a thread stripping phenomenon often occurs in a process of assembling a complex die-casting fitting because EN 44300 has low rigidity. ADC1 and ADC12 in aluminum alloys with Japanese designations have excellent formability, but low corrosion resistance, especially the ADC12 alloy. Even though surface coating is performed, the complex communications die-casting fitting still cannot be applied to a seaside environment. In view of this, developing a die casting aluminum alloy having high heat conductivity, high corrosion resistance, good formability, and certain mechanical properties currently has become an urgent demand of the communications industry.